Ophrydesmus kedahensis ( Wang & Tang, 1965 )

Golovatch, Sergei I., 2018, Further notes on the millipede family Cryptodesmidae in Southeast Asia, with descriptions of a new genus and two new species from Indochina (Diplopoda: Polydesmida), Raffles Bulletin of Zoology 66, pp. 361-370 : 368-370

Ophrydesmus kedahensis ( Wang & Tang, 1965)

( Figs. 7–8 )

Phenacoporus kedahensis Wang & Tang, 1965: 425 (D).

Phenacoporus kedahensis — Wang, 1967: 396 (R).

Ophrydesmus kedahensis — Decker, 2013: 15 (R); Golovatch, 2015: 158, 163 (R, D).

Descriptive notes and remarks. This species was originally described as Phenacoporus kedahensis Wang & Tang, 1965 , from the male holotype coming from “Baling Ledah”, likely the town of Baling in the southeastern part of a slightly misspelled state of Kedah, northern Western Malaysia, as well as from a female paratype (allotype) stemming from Singapore ( Wang & Tang, 1965). The species name itself, kedahensis , clearly suggests its provenance from Kedah. A little later, Wang (1967) recorded another female from Bukit Timah, Singapore, again referring the species to Phenacoporus Attems, 1914 . Decker (2013) was the first to formally transfer P. kedahensis to Ophrydesmus Cook, 1896 , based on Jeekel (1955) who had synonymised Phenacoporus under Ophrydesmus , a synonymy Wang & Tang (1965) and Wang (1967) had overlooked.

The original description of this species ( Wang & Tang, 1965) had been so poor, and the single sketch of a gonopod so crude, that Golovatch (2015), in his review of Ophrydesmus , incorporated O. kedahensis and several other, largely female-based cryptodesmid species from Indonesia into that genus only with reservations. Now that the first meaningful illustrations of O. kedahensis have become available ( Figs. 7 , 8 ), a more solid opinion can finally be expressed.

The length of the body was said to vary from 8 mm (female non-type from Singapore) to 12.5 mm (paratype) or even 13 mm (holotype). The holotype, in ZRC, is fragmented, but complete, with 20 body segments, representing a typical cryptodesmid. The collum is flabellate, completely covering the head from above, with 10+10 faint lobulations and 19 radii at the anterior margin. Each postcollum metatergum is with four transverse rows of small, squarish, setigerous, non-differentiated tuberculations only partly extending onto paraterga; each postcollum paratergum is with a faintly bordered, slightly and regularly rounded anterior margin/ shoulder increasingly clearly declined caudally only on segments 14–19; the lateral margin of each paratergum bears four small setigerous lobulations, the anterolateral corner being mostly narrowly rounded and squarish; the caudal margin is with 7+7, laterad increasingly evident, setigerous lobulations between the caudolateral ones and the bases of paraterga ( Fig. 7 ) .

Male femur 3 is clearly inflated ( Fig. 7B ), sternal cones seem to be present.

The gonopods ( Fig. 8 ) are relatively simple, in situ held parallel to each other; the telopodites are distinctly biramous, the anterior branch (ap) being much larger, higher, curved caudad, slightly enlarged and folded distomesally, broadly rounded at the apex. The caudal branch (cp) is considerably lower, smaller, roundish and even more simple than ap, with a folded seminal groove/solenomere (sl) being visible at the bottom between both ap and cp. The gap between ap and cp is deep and considerable.

The above characters, particularly the gonopodal conformation and the presence of an inflated male femur 3, are definitely evidence of the correct assignment of O. kedahensis to Ophrydesmus . Moreover, its affinities to the first four congeners that Cook (1896) originally described from Java, Indonesia are especially clear, as they all share inflated male femora 3 and evident sternal cones ( Attems, 1940; Golovatch, 2015): O. gede Cook, 1896 (the type species of Ophrydesmus and a junior synonym of O. weberi ( Pocock, 1894) , the latter taxon the type species of Phenacoporus , synonymised by Jeekel (1955), O. pugnus Cook, 1896 , O. scaurus Cook, 1896 , and O. tengger Cook, 1896 . Among these, only O. weberi is known to occur partly sympatrically with O. kedahensis , i.e., western Java, Indonesia and Singapore ( Decker, 2013). However, both are distinct enough through the former species showing a larger body (16–20 mm long and 4.0–5.0 mm wide on midbody pro- and metazonae, respectively), mostly five transverse rows of metatergal tuberculations and the gonopodal telopodites clearly less strongly excavate between both branches, the basal (= caudal, or main) of which is much smaller and different in shape ( Attems, 1940). Based on the available key ( Golovatch, 2015). O. kedahensis is sufficiently distinct from the other congeners as well.

As a result, O. kedahensis is an independent species, Golovatch’s (2015) key to Ophrydesmus spp. holds basically valid, but O. kedahensis must be transferred inside couplet 5(6) which unites the congeners characterised by inflated male femora 3 and the presence of sternal cones.

Figures

Fig. 7.Ophrydesmus kedahensis (Wang & Tang, 1965), fragmented male holotype from Baling, Kedah, Malaysia. Habitus, A, dorsal view; B, ventral view. Scale bar = 1.0 mm.

Fig. 8. Ophrydesmus kedahensis (Wang & Tang, 1965), male holotype from Baling, Kedah, Malaysia. A, Segment 7 with gonopodal aperture and an intact left gonopod in situ, ventral view; B, removed right gonopod, sublateral view; C, removed right gonopod, submesal view; D, enlarged telopodite of left gonopod, submesal view. Scale bar = 1.0 mm (A–C) or not to scale (D). Designations: ap = anterior process; cp = posterior process; sl = solenomere.